He says to get the most out of exercise we should work within our body’s natural range of movement.

So he’s come up with the seven sins of the gym – the most common exercises that should be avoided.

He tells MARIA CROCE which exercises to avoid and what’s safer…

1. Dips

Greg says: “The Dips exercise has been around for a long time and there are special bars in gyms for people wanting to do these. But they’re not good for your shoulders. Lowering yourself down too far under your full bodyweight during the dip exercise puts your shoulder capsule under strain.

“The arms are not designed to go back like that. You can test this yourself if you stand up tall and see how far you can naturally take your arms backwards. Avoid dips because you’re stretching all your ligaments and the soft tissue of the shoulder joint which could leave you with unstable shoulder joints that are more likely to dislocate.”

Greg says: “Most gyms have a Lat Pull Down machine which is a T-bar on a cable. It’s ok to pull the bar down to your upper chest – but pulling it behind your head is bad for your shoulder joints.

“This movement externally rotates the shoulder joint more than it should naturally go.”

Safer Alternative: Pull Downs to the Upper Chest or even better Chin Ups

3. Sit Ups or Crunches

Greg says: “If you’re lying on the floor doing crunches and sit ups, then you’re only covering half of the natural movement of the spine. These exercises don’t tie in with our natural daily movements and go against our posture especially as we spend most of our days hunched over a desk. You’re better to try to build more core stability. If you want to do this exercise then it’s best to crunch over a stability ball to move the spine through a full range of movement.”

Safer Alternative: Planks, Woodchops, Stability Ball Jack Knife

4. Unprepared running

Greg says: “I’m not against running, but if you’re starting off, then lose excess weight through diet and perform bodyweight exercises to improve your core strength and stability of your joints first. Running puts a big strain on the body because more than three times your bodyweight goes through each leg during each stride. To be able to absorb this shock, the body has to have good alignment and core strength.

“If you’re not properly prepared and you take up running there’s a good chance you may end up with some kind of injury within the first four weeks.”

Safer Alternative: Bodyweight Circuits or Hill Walking Intervals

5. Deep Bench Press

Greg says: “Lifting weights using the bench press can be a great way to build muscle and strength in the shoulders, chest and triceps – but you have to be careful. When you’re loading the barbell don’t take the weight down too low. Taking it down to touch your chest, or lower if using dumbbells, is usually too much for most shoulders to handle.

“To check how far you can go naturally, experiment with a broomstick. Then you’ll realise it’s the weight of the barbell which is taking the bar down lower than you should go.”

Safer Alternative: Test your natural range and stay within it

6. Hamstring Curls

Greg says: “There’s a gym machine where you lie down on your front and pull your heels up to your backside. Bodybuilders use this to isolate the hamstring muscles – but lying down in this position overloads the knee joints as well as the lower back.

“Using this type of machine puts your body in an unnatural position and makes your joints work on their own – rather than with the rest of the body which is how they’re designed to deal with load.”

Safer Alternative: Deadlifts or Single Leg Deadlifts

7. Smith Machine Squats

Greg says: “You have to make sure you learn to squat properly. It’s one of our most natural movements we go through every day, when we sit down or stand up.

“The Smith machine has a bar that follows a vertical path when you squat – which isn’t the natural way we should perform this exercise. During a natural squat your upper body leans forward and your hips push backwards – you shouldn’t be staying vertical as this machine encourages.”